This invention relates to pumping systems of the type particularly suitable for shipboard use or use in similar applications. On naval ships there is normally available an engine-driven fire pump ready for use in case of a fire. The reliability of the fire pump for emergency use must be 100%. However, during normal conditions, the actual use of these fire pumps is for dewatering purposes. Accordingly, the typical navy fire pump is a centrifugal pump designed to be able to handle both fire fighting and dewatering operations. In some dewatering operations, the engine and fire pump must be taken down the hold, thereby requiring, for safety, the provision of an engine exhaust hose which must be run a substantial distance, the exhaust hose serving to remove the engine-produced carbon monoxide from the hold. Also, in many cases it is necessary to lift the water a substantial distance and since centrifugal pumps are limited in how high they can lift water, special equipment, such as eductors, may have to be used in high lift applications.
It is the general object of the invention to provide a pumping system of the indicated type which eliminates the necessity of taking the pump down into the hold, thereby also avoiding the carbon monoxide safety problem, and which overcomes the lift problems faced by the prior art pumping systems.
Briefly stated, the general object of the invention is achieved by providing a submersible centrifugal pump which is driven by a small compact high pressure hydraulic motor. The hydraulic motor is mounted directly onto the submersible pump so that the hydraulic motor and submersible pump can be submerged together in the hold. A hose means, including a retractable reel, is connected from the hydraulic motor to a hydraulic pump located up on deck along with the engine-driven fire pump. The hydraulic pump is arranged to be drivingly connected to the fire pump output shaft.
The pumping system of the invention can be operated in several modes. For example, in the event that there is a need for dewatering, the hydraulic pump and hydraulic motor unit is connected to be driven by the fire pump and to drive the submersible pump which is submerged at the location where the dewatering is to be achieved. A retractable reel is provided to permit locating of the submersible pump at remote locations. The submersible pump is designed to provide just enough pumping pressure to lift water over the side of the ship. Thus, the submersible pump is designed to be a high volume, low pressure type of pump while the fire pump is a low volume, high pressure type of pump particularly adapted for fire fighting applications. Thus, each pump is designed for its primary use.
In the fire fighting mode of the pumping system, the hydraulic pump is disconnected from the fire pump and the engine-pump unit operates in conventional manner for the fighting of fires or the like.
In a third mode of operation, the pumping system supplies a source of power for safely operating various emergency power tools in holds or under water, etc. With the engine being remotely operated, the exhaust gases can safely escape without danger to the crew members.
A further mode of operation of the pumping system of the invention involves the use of a separate engine drive for both the fire pump and the hydraulic pump permitting performing of both fire fighting and dewatering operations.
In addition, the pumping system of the invention can be set up so that the hydraulic pump is used to drive various types of hydraulically operated devices, such as any of the hydraulically operated tools used on ships including hydraulic ram devices, hydraulic motor driven tools like saw blades, etc.
An important advantage of the pumping system of the invention is that it can be made to be light in weight so that it is portable. The advantage results from the design whereby the hydraulic unit is quickly detachable from the engine-driven unit, i.e., the hydraulic pump and motor unit is a separate unit from the engine-drive fire pump.
In another embodiment of the invention a discharge line from the fire pump is arranged to drive a water motor which is mounted on the submersible pump for driving the same.